Hershberger assay to investigate the effects of endocrine-disrupting compounds with androgenic or antiandrogenic activity in castrate-immature male rats.

The protocol described in this unit is designed to evaluate the effects of androgenic and antiandrogenic endocrine-disrupting compounds (EDCs) in the castrate-immature male rat. Continuous 10-day exposure of the prepubertal male to chemicals is used to identify androgenic or antiandrogenic activities based on the weights of several androgen-dependent tissues on the day after treatment is ended. Androgen-dependent organ weights and growth, along with kidney, liver, and adrenal weights are measured at necropsy. The androgen-dependent tissues include the ventral prostate, seminal vesicles (with fluid plus coagulating glands), levator ani plus bulbocavernosus muscles, Cowper's glands, and glans penis. Optional measures, which facilitate interpretation of the data when positive effects are detected, include serum testosterone and luteinizing hormone levels. Androgenic chemicals cause increases in one or all of the androgen-dependent tissue weights after being administered by oral gavage or subcutaneously (s.c.) to castrate-immature male rats. Antiandrogenic chemicals cause reductions in androgen-dependent tissue weights after being coadministered with testosterone propionate (s.c.).